/*#include<stdio.h>
int main()
{
	int a,b;
	float sum,i,t,sum1,sum2;
	sum1=sum2=0;
	for(a=1;a<=100;a+=2)
	{
		i=1/a;
		sum1+=i;
	 } 
	 for(b=2;b<=100;b+=2)
	 {
	 	t=-1/b;
	 	sum2+=t;
	 }
	 sum =sum1+sum2;
	 printf("%f %f ",sum1,sum2);
	 printf("%f",sum);
	return 0;
}
}*/
#include<stdio.h>
int main()
{
	int a,b;
	double i,t,sum1,sum2,sum;
	i=0.0;
	t=0.0;
	for(a=0;a<=100;a+=2)
	{
		i=1.0/a;
		sum1+=i;
	}
	for(b=1;b<100;b+=2)
	{
		t=-1.0/b;
		sum2+=i;
	}
	sum=sum1+sum2;
	printf("%d",sum);
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	return 0;
}
